The Quantum Mechanical Model of the Atom
- Since Bohr Model was unable to explain and make predictions about multi-electron atoms, new approach was needed ( occurred mid 1920's)
- Approach that was taken (which is the currently accepted model) is called the wave mechanics or quantum mechanics
- Quantum mechanics is the study of motion at the atomic level where laws of classical motions do not apply because particles behave like waves (dual nature of matter)
- 3 physics were at the forefront of this model which were Erwin Schrodinger, Louis de Broglie and Werner Heisenberg
- de Broglie originated idea than an electron has both waves and particle properties ( i.e. dual nature of matter)
-Schrodinger then focused on wave properties of the electron
- To Schrodinger and de Broglie an electron bound to an nucleus resembled a standing wave
-They took idea of standing waves and applied it to the electron in hydrogen
- Their model showed the electron as a circular standing wave with wavelengths of whole number multiples (n=1,2,3,4...)
- Any other orbits would cause the standing wave to cancel out or collapse
- Schrodinger's work led to the development of the Schrodinger wave equation which can be used to calculate electron energy levels
- This gave definable amount of energy to an electron allowing it to be localized to a given orbital ( a region around nucleus where there is a high probability of finding an electron).
-However, electrons are so small that any attempt to measure its location or speed will affect its location and/or speed
- This formed basis of Heisenberg's Uncertainty Principle which is idea that it is impossible to know exact position and speed of an electron at a given time
- Best that can be done is to describe probability of finding an electron in a specific location
- The "shapes" of electron orbitals are 3D electron probability densities created by physicists using wave functions (mathematical probability of finding an electron in a certain region of space)
- Electrons have ability to jump to these different orbitals if they absorb sufficient quanta of energy
- 2 main points of Quantum Mechanical model were:
1. Electrons can be in different orbitals by absorbing or emitting quanta of energy
2. The location of electrons is given by a probability distribution.
Melissa Chan June 1, 2015
Electron Configuration and Energy Level Diagrams
Electron Configurations
shows the specific placement of electrons within an energy level
orbitals are the sub-levels of an energy level, and
can hold a maximum of two electrons
four types of orbitals exist
s orbital: single
p orbital: group of 3
d orbital: group of 5
f orbital: group of 7
every energy level has an s orbital, p orbitals are found at energy level 2 and above, d orbitals are found at energy 3 and above, f orbitals at energy level 4 and above
some orbitals at a higher energy level are closer to the nucleus due to overlapping
Example electron configuration for europium, Eu:
Example short form electron configuration for darmstadtium, Ds.
Energy Level Diagrams
show how electrons are placed within orbitals
orbitals are represented with lines () or circles (O)
electrons are represented by up/down arrows or half arrows
Aufbau Principle:lowest energy levels filled first
Hund's Rule: each orbital gets a single electron before pairing when there are multiple levels of equal energy
Pauli Exclusion Principle:__ when two electrons are placed within same orbital, they will spin in different directions
shown by placing first electron pointing up, the second electron pointing down
Sankave Muraleetharan Tuesday June 9th, 2015
In today’s class, Ms. Wilson was away therefore we did not have a lesson. The task that she had left us to do was to study for the Chemistry exam (Monday June 15th, 2015 at 1:00 pm) and also if you do not have the worksheets, please check the chemistry wiki page. Here is a direct link that will lead you to the EXAM REVIEW:__https://sch4uking.wikispaces.com/Exam+Review__
Studying Tips/Adivce: -Never study the day before -Read through your notes and do practice problems -Check online sources for more help such as video tutorials (Remember Khan Academy is not recommended) -Make flash cards with information of your choice -Do not pull an all nighter the day before the exam Sankave Muraleetharan Wednesday June 10th, 2015
In today’s class, Ms. Wilson gave us the period to study for the exam. Reminder: the Chemistry exam is on Monday June 15th, 2015 at 1:00 pm. Remember to bring your textbook with you, if you don’t bring it, or misplaced/lost it, please go to the office and get a note in order to write the exam.
Focus on the unites we spent more days on learning. Just because we learned Electron Configuration last and did not have a test on it, does mean there is going to be a lot of questions on that unit.
Studying for chemistry can be stressful! For those who are lost in what to do and do not know any studying tips, here is a link that gives you a list on how to prepare yourself. This links will actually help! __http://www.wikihow.com/Pass-Chemistry__ Here is another link that would give you great tips for exams ingeneral : __http://www.topuniversities.com/student-info/health-and-support/exam-preparation-ten-study-tips__
Remember, if you are going to search for tutorials online,do not watch Khan Academy as it does not teach the actual chemistry, Ms. Wilson taught us! Here are videos that gives you a unit review: Energy Change & Rate of Reactions:__https://www.youtube.com/watch?v=w0mb0BIEkBI__ Electrochemistry: __https://www.youtube.com/watch?v=IV4IUsholjg__ Reference: CrashCourse. (2013, October 29). Electrochemistry: Crash Course Chemistry #36 [Video file]. Retrieved from https://www.youtube.com/watch?v=IV4IUsholjg Exam Preparation: Ten Study Tips | Top Universities. (n.d.).Retrieved from http://www.topuniversities.com/student-info/health-and-support/exam-preparation-ten-study-tips How to Pass Chemistry (with Pictures) - wikiHow. (n.d.).Retrieved June 10, 2015, from http://www.wikihow.com/Pass-Chemistry Oliver, C. (2013, November 6). Chapter 6: Energy Changes, Reaction Rates, and Equilibrium [Video file]. Retrieved from https://www.youtube.com/watch?v=w0mb0BIEkBI
Atomic Structure PPT
By: Hafshan Hameem
29/05/2015
The Quantum Mechanical Model of the Atom
- Since Bohr Model was unable to explain and make predictions about multi-electron atoms, new approach was needed ( occurred mid 1920's)
- Approach that was taken (which is the currently accepted model) is called the wave mechanics or quantum mechanics
- Quantum mechanics is the study of motion at the atomic level where laws of classical motions do not apply because particles behave like waves (dual nature of matter)
- 3 physics were at the forefront of this model which were Erwin Schrodinger, Louis de Broglie and Werner Heisenberg
- de Broglie originated idea than an electron has both waves and particle properties ( i.e. dual nature of matter)
-Schrodinger then focused on wave properties of the electron
- To Schrodinger and de Broglie an electron bound to an nucleus resembled a standing wave
-They took idea of standing waves and applied it to the electron in hydrogen
- Their model showed the electron as a circular standing wave with wavelengths of whole number multiples (n=1,2,3,4...)
- Any other orbits would cause the standing wave to cancel out or collapse
- Schrodinger's work led to the development of the Schrodinger wave equation which can be used to calculate electron energy levels
- This gave definable amount of energy to an electron allowing it to be localized to a given orbital ( a region around nucleus where there is a high probability of finding an electron).
-However, electrons are so small that any attempt to measure its location or speed will affect its location and/or speed
- This formed basis of Heisenberg's Uncertainty Principle which is idea that it is impossible to know exact position and speed of an electron at a given time
- Best that can be done is to describe probability of finding an electron in a specific location
- The "shapes" of electron orbitals are 3D electron probability densities created by physicists using wave functions (mathematical probability of finding an electron in a certain region of space)
- Electrons have ability to jump to these different orbitals if they absorb sufficient quanta of energy
- 2 main points of Quantum Mechanical model were:
1. Electrons can be in different orbitals by absorbing or emitting quanta of energy
2. The location of electrons is given by a probability distribution.
Melissa Chan
June 1, 2015
Electron Configuration and Energy Level Diagrams
Electron Configurations
Example electron configuration for europium, Eu:
Example short form electron configuration for darmstadtium, Ds.
Energy Level Diagrams
Example energy level diagram for cobalt:
Homework: none
Resources
Electron Configuration of Atoms
Drawing Energy Level Diagrams
Sankave Muraleetharan
Tuesday June 9th, 2015
In today’s class, Ms. Wilson was away therefore we did not have a lesson. The task that she had left us to do was to study for the Chemistry exam (Monday June 15th, 2015 at 1:00 pm) and also if you do not have the worksheets, please check the chemistry wiki page. Here is a direct link that will lead you to the EXAM REVIEW:__https://sch4uking.wikispaces.com/Exam+Review__
Studying Tips/Adivce:
-Never study the day before
-Read through your notes and do practice problems
-Check online sources for more help such as video tutorials (Remember Khan Academy is not recommended)
-Make flash cards with information of your choice
-Do not pull an all nighter the day before the exam
Sankave Muraleetharan
Wednesday June 10th, 2015
In today’s class, Ms. Wilson gave us the period to study for the exam. Reminder: the Chemistry exam is on Monday June 15th, 2015 at 1:00 pm. Remember to bring your textbook with you, if you don’t bring it, or misplaced/lost it, please go to the office and get a note in order to write the exam.
Focus on the unites we spent more days on learning. Just because we learned Electron Configuration last and did not have a test on it, does mean there is going to be a lot of questions on that unit.
Studying for chemistry can be stressful! For those who are lost in what to do and do not know any studying tips, here is a link that gives you a list on how to prepare yourself. This links will actually help! __http://www.wikihow.com/Pass-Chemistry__
Here is another link that would give you great tips for exams ingeneral : __http://www.topuniversities.com/student-info/health-and-support/exam-preparation-ten-study-tips__
Remember, if you are going to search for tutorials online,do not watch Khan Academy as it does not teach the actual chemistry, Ms. Wilson taught us!
Here are videos that gives you a unit review:
Energy Change & Rate of Reactions:__https://www.youtube.com/watch?v=w0mb0BIEkBI__
Electrochemistry: __https://www.youtube.com/watch?v=IV4IUsholjg__
Reference:
CrashCourse. (2013, October 29). Electrochemistry: Crash Course Chemistry #36 [Video file]. Retrieved from https://www.youtube.com/watch?v=IV4IUsholjg
Exam Preparation: Ten Study Tips | Top Universities. (n.d.).Retrieved from http://www.topuniversities.com/student-info/health-and-support/exam-preparation-ten-study-tips
How to Pass Chemistry (with Pictures) - wikiHow. (n.d.).Retrieved June 10, 2015, from http://www.wikihow.com/Pass-Chemistry
Oliver, C. (2013, November 6). Chapter 6: Energy Changes, Reaction Rates, and Equilibrium [Video file]. Retrieved from https://www.youtube.com/watch?v=w0mb0BIEkBI